Patriot Coal Corporation (PCX) garnered heavy call volume Monday on the International Securities Exchange (ISE). During the course of the session, traders on the ISE bought to open 1,264 calls on PCX, compared to just 50 puts, for a single-day call/put volume ratio of 25.28.

Patriot Coal Corporation (PCX) garnered heavy call volume Monday on the International Securities Exchange (ISE). During the course of the session, traders on the ISE bought to open 1,264 calls on PCX, compared to just 50 puts, for a single-day call/put volume ratio of 25.28.

Most of the day's volume was concentrated at the June 10 strike, where 2,628 calls changed hands on open interest of 2,722. Many of these transactions consisted of newly opened positions, with open interest on the June 10 call arriving today at 4,597 contracts. This strike is now home to peak call open interest in the front-month series.

In today's trading, it's the September 10 call that's attracting speculative attention. This option has seen 1,354 contracts cross the tape on open interest of 1,155, suggesting that a portion of today's volume will translate to new open interest tomorrow.

On the charts, PCX is hovering just fractions of a point below this closely watched round-number strike. The commodity issue hasn't closed a single week in double-digit territory since early November 2008.